Skeletal muscle oxidative capacity and tissue composition in heart failure with preserved ejection fraction

We compared peripheral mechanisms of exercise intolerance in heart failure with preserved ejection fraction (HFpEF) patients and healthy older adults. HFpEF patients exhibited significantly greater intermuscular steatosis and impaired whole body and quadriceps oxidative capacity [i.e., peak O ₂ uptake (V̇o _2peak ) and phosphocreatine recovery time constant (τPCr), respectively], all of which were associated with impaired exercise tolerance. However, increased intermuscular steatosis was not associated with impaired V̇o _2peak and τPCr, suggesting that steatosis and impaired oxidative capacity affect exercise tolerance through different physiological mechanisms.